Velleman K8066 HELP!!!

[montmont]

Im new to the audio hobby but i had put together a velleman k8066 amplifier chip everything is soldered properly but the sound coming from my speaker is sounding distorted. I have a 9volt battery hooked up to it as the power supply. In the book its says power supply between 6 and 15vdc. One last question is there any way to build like a tube or something so that my speaker will sound louder?

[Minion]

Well , the amp only does 3w at 10% THD with a 15v DC supply so with a 9v supply you will do less than 2w at 10% THD so depending on your speaker you might have to push the amp pertty hard to get it loud and at full power it will be fairly distorted ......

I would suggest trying a 15v DC supply which will give you a bit more headroom and output power and if it is still not loud enough or too distorted you could try a more sensitive speaker , otherwize a more powerfull amp will be needed ......

Good luck

[!]

Note on the kit details it lists 500mA max current consumption. A mere 9V battery cannot supply enough current and the power rail voltages will collapse. You might have better results with a "battery" consisting of 8 x AA NiMH cells in series. 9V battery (PP3 form factor) isn't suitable for powering much more than a headphone amp.

So, you need a different power source. TDA7267A can use up to 18V power rail, try powering it with a typical 12VDC, 500mA or higher current rated brick/wall plug type supply if you have nothing else available. I mention that type mainly because they are common as dirt, you probably have some old ones lying around or can find one pretty easily.

If you're hooking it up to a bare speaker driver it's going to sound different than a driver in a cabinet would. Until you are sure the amp works right, keep using a cheap/throwaway bare speaker driver but once it seems to work ok, hook it up to a better speaker in a cabinet. ~1W to 2W at median speaker efficiency won't be loud but still quite usable for some purposes.

Of course, if you want much higher output power you'll need a more robust amp chip and power supply. The amp you are building is equivalent to about what you would get in a $8 USD pair of computer speakers.